A libsdl regression in asm routines causes the audio output through ALSA to crakle. This issue only reproducible on x86 there is no assembly for other architectures. Reproducible: Always Steps to Reproduce: 1. USE=-ao emerge zsnes (or any SDL game) 2. SDL_AUDIODRIVER=alsa zsnes (or any other game of your choice) 3. Actual Results: sound crackles. Expected Results: smooth sound. libsdl needs to be configured with --disable-assembly for ALL architectures, not just non-x86. Not sure what the performance penalty will be for other audio output modules. Perhaps make this into a USE flag? See libsdl bug report: http://bugzilla.libsdl.org/show_bug.cgi?id=649
Created attachment 190993 [details] Disable MMX assembly in libsdl/src/audio/SDL_mixer.c This patch fixes this bug for SDL audio part only, not affecting other assembly.
Proposed patch fixed sound in sauerbraten (cube 2) for me.
Created attachment 190995 [details] Proposed ebuild to use libsdl-1.2.13-disable-mmx-mixer.patch Put it to overlay to media-libs/libsdl, put libsdl-1.2.13-disable-mmx-mixer.patch to the media-libs/libsdl/files subdir.
I can't reproduce this. I'm not really inclined to turn off the assembly routines outright unless you can narrow down the cause of the failure or show exactly how to reproduce the issue so I can see it here.
marking WORKSFORME. reopen with more information if you can.
*** Bug 283297 has been marked as a duplicate of this bug. ***
Is fixed in SDL 1.2.14